焦化苯中噻吩在改性ZSM—5分子筛上吸附动力学研究

本文系统地 用改性ZSM－5分子筛吸附脱除焦化苯中噻吩过程动力学，测定了池式吸附曲线，提出了可以较好地描述苯－噻吩－ZSM－5吸附体系的动力学模型，模型中考虑了大孔扩散，表面扩散和吸附一反应阻力等吸附过程，并通过实验数据求得了大孔扩散系数，表面扩散系和吸附速度常数等吸附动力学参数与温度的关系，在该吸附过程中，大孔扩散，表面扩散和吸附反应过程都起着重要作用。     

改性活性碳吸附净化黄磷尾气中的磷化氢

为综合利用黄磷尾气中的高浓度CO气体，通过钢瓶配气模拟和气相色谱GC-14C测定的方法，研究了HCI改性活性碳吸附净化黄磷尾气中PH3的相关问题。结果表明：较适宜的改性剂为质量分数为5％的盐酸；无氧时较适宜温度为20℃，有氧时较适宜温度为70℃；较适宜氧体积分数为1％；孔径和热重差热分析初步证明吸附质主要为磷和磷氧化物，酸改性活性碳上孔径〈1．5nm的微孔对PH3的吸附反应贡献较大，吸附质失重主要发生在0-100℃阶段。     

改性分子筛吸附脱硫

以ZSM-5、Y型、MCM-41分子筛为载体,采用离子交换法制备了一系列用于汽油脱硫的负载金属离子的改性分子筛吸附剂。对不同的吸附剂作了X-射线衍射和比表面积分析,考察了静态吸附条件对其脱硫性能的影响。结果表明,不同吸附剂对噻吩的吸附效果不同,CuY的效果较为明显,并得出适宜的吸附条件:常温,常压,剂油质量比为0.15。通过对再生前后吸附剂CuY的变化分析,对吸附脱硫的机理进行了探讨。     

铁改性13X分子筛吸附水中氟离子的实验

用经Fe3+溶液改性的13X分子筛对水溶液中氟离子进行了吸附实验.实验结果表明:该分子筛的吸附效果与改性时离子交换度、分子筛用量成正比;通过正交实验,确定出影响吸附效果的主要因素.     

铁改性13X分子筛吸附水中氟离子的实验

用经Fe3 溶液改性的13X分子筛对水溶液中氟离子进行了吸附实验。实验结果表明:该分子筛的吸附效果与改性时离子交换度、分子筛用量成正比;通过正交实验,确定出影响吸附效果的主要因素。     

改性活性炭吸附净化二氧化硫实验研究

本试验装置采用固定床吸附柱,以经过酸改性活性炭作为吸附剂,吸附剂比表面积约为1200 m2/g,吸附质为模拟SO2废气。在不同入口气体浓度下,测定吸附质出口浓度,绘制吸附净化穿透曲线图,并由此计算出静活性值。试验结果表明:吸附柱填装活性炭量为100g,气体流量50L/min,大气压为101300Pa,温度20℃,吸附质浓度在500～1000ppm间变化时,活性炭吸附剂的静活性值平均提高30%,改性的活性炭静活性值比未改性活性炭平均提高25%。     

MCM-41与5A分子筛二氧化碳吸附特性对比

以5A分子筛和MCM-41为基体,环氧树脂(EP)作交联剂,四乙烯五胺(TEPA)作改良剂,采用浸渍法制备了一系列胺基吸附分子筛。利用低温N2吸附/脱附和红外等方法考察了改性前后样品的结构特征,研究了温度在323,333,343和353K下改性分子筛对CO2吸附量的大小。结果表明:经过TEPA改性后,5A分子筛和MCM-41分子筛的结构特征得到了很好地保持,比表面积和孔容随着TEPA负载量的增加而降低。改性MCM-41分子筛比改性5A分子筛吸附效果好。在温度为333K,CO2初始体积分数为15%时,改性MCM-41分子筛最大吸附量为3.2mmol·g~(-1)。     

5A和VP800分子筛的氮氧分离性能

在298.15 K下,分别测定了5A和VP800分子筛的静态吸附等温线和动态穿透曲线,并根据动态穿透曲线分别计算出5A和VP800分子筛的氮氧分离系数。研究发现,VP800分子筛的氮氧分离选择性明显高于5A分子筛。从动态吸附的结果来看,VP800有一个最优的吸附分离压力。     

乳酸制备丙烯酸用金属离子改性4A分子筛研究

采用浸渍法制备了负载金属离子负载4A分子筛催化剂,采用Cu2＋、Ba2＋、La2＋对4A分子筛催化剂进行改性,采用BET、IR、XRD对催化剂的比表面积及结构和品相进行了表征;在一定的条件下,将改性催化剂用于乳酸制备内烯酸的反应。实验结果表明,浸渍液硝酸钠质量分数为30％,负载的金属离子为Ba＋催化剂的比表面积增大,催化剂的晶型结构发牛了变化;当乳酸质量分数为40％,Nz流量为2．0m1．／min,反应温度为325℃,催化剂质量为0．3g时,丙烯酸的产率达到最高,为29．5％,转化率为70％左什。     

沸石分子筛对水中钙离子的吸附研究

对沸石分子筛去除水中钙离子的吸附情况进行了系统的研究.考察了温度、pH值、不同粒径等因素对吸附量的影响.结果表明:4A分子筛与13X分子筛对钙离子均具有较好的吸附效果,两种分子筛对钙离子的最大饱和吸附量分别达到51.97和49.30 mg/g.     

H-STI分子筛对氨分子的吸附分子模拟

采用巨正则蒙特卡罗方法(GCMC)研究了氨分子在H-STI分子筛中的吸附特性.计算得到的吸附热和实验温度下吸附等温曲线与实验结果吻合较好,在此基础上,进一步预测了氨分子在H-STI分子筛中的吸附性质.     

Effects of Assistant Agent on Mesoporous Structure of Silica MCM-41 Molecular Sieves

The nanostrutured mesoporous silica materials MCM- 41 with different pore sizes were synthesized by adding 1,3,5-trimethylbenzene (TMB) as assistant agent in the reactant mixture. The obtained samples were investigated by XRD, HRTEM, FTIR and N2 adsorptions. It is shown that the pore sizes, ordered degree and specific surface area increase effectively with the incremented addition of TMB in an appropriate range, but the (100) peak intensity of XRD pattern becomes weakened and the ordered degree decreases when the additive quantity continued to increase. With the addition of TMB in an appropriate range, the effective surfactant ion pair packing parameter, g=V/ao l, is mediated in the range of 1/3- 1/2 with the increment of V and l, indicating that mesoporons silica is a well-ordered hexagonal structure. Howvever, when the addition of TMB increases, g value becomes larger, which leads to a less long-range ordered structure for the uneven condissolution of TMB.     

于沸石分子筛ZSM-5中组装Fe3O4的新方法及其磁性

首次以分步水热合成法于孔径为0.56 nm的沸石分子筛ZSM-5的孔道中成功地组装了铁氧体Fe3O4,并测出了它们的磁滞回线及磁学参数:饱和磁化强度σs、剩余磁化强度σr和矫顽力Hc.实验表明,体相Fe3O4的矫顽力为102 Oe,组装后变小为14Oe,即由体相强磁性材料变为纳米非晶软磁材料,这是纳米粒子的小尺寸效应和量子尺寸效应所致,并由XRD,IR,磁滞回线得到了表征.     

Influence of CYP3A5 polymorphism on tacrolimus blood concentrations in renal transplant patients

Objective Tacrolimus is an immunosuppressive drug with narrow therapeutic range and wide interindividual variation in its pharmacokinetics. Tacrolimus is a substrate of cytochrome P450(CYP)3A5. The aim of this study was to evaluate whether the A6986G polymorphism is associated with tacrolimus concentration /dose ratio. Methods Fifty-two Chinese renal transplant patients were enrolled in this study. Their body weight, dosage and concentration of tacrolimus were observed. CYP3A5 genotype was determined by polymerase chain reaction followed by restriction fragment length polymorphism analysis. Results A significant association was found between tacrolimus levels per dose/kg/d and CYP3A5 gene A6986G polymorphism (P<0.001). The CYP3A5 * 3 * 3 patients have a significantly higher tacrolimus level/dose than CYP3A5 * 1 * 1 and CYP3A5 * 1 * 3. Conclusions CYP3A5 gene A6986G polymorphism is associated with tacrolimus pharmacokinetics and dose requirements. Pharmacogenetic methods could be employed prospectively to help the dose selection and to individualize immunosuppressive therapy according to the result. Foundation item: Project (03GZ3072) supported by the Science and Technology Department of Hunan Province; project (2004035206) supported by the China Postdoctoral Foundation and project (30300383) supported by the National Natural Sciences Foundation of China     

Influence of CYP3A5 polymorphism on tacrolimus blood concentrations in renal transplant patients

Objective Tacrolimus is an immunosuppressive drug with narrow therapeutic range and wide interindividual variation in its pharmacokinetics. Tacrolimus is a substrate of cytochrome P450(CYP)3A5. The aim of this study was to evaluate whether the A6986G polymorphism is associated with tacrolimus concentration/dose ratio.Methods Fifty-two Chinese renal transplant patients were enrolled in this study. Their body weight, dosage and concentration of tacrolimus were observed. CYP3A5 genotype was determined by polymerase chain reaction followed by restriction fragment length polymorphism analysis. Results A significant association was found between tacrolimus levels per dose/kg/d and CYP3A5 gene A6986G polymorphism(P＜0.001). The CYP3A5 * 3 * 3 patients have a significantly higher tacrolimus level/dose than CYP3A5 * 1 * 1 and CYP3A5 * 1 * 3. Conclusions CYP3A5 gene A6986G polymorphism is associated with tacrolimus pharmacokinetics and dose requirements. Pharmacogenetic methods could be employed prospectively to help the dose selection and to individualize immunosuppressive therapy according to the result.     

微波辐射条件下SAPO-5分子筛的合成与表征

以异丙醇铝、磷酸、正硅酸乙酯为反应原料,三乙胺作为模版剂,功率800 W、180℃微波辐射30min合成了粒径均一、具有AFI拓扑结构的SAPO-5分子筛,系统研究了Al2O3与SiO2摩尔比和HF添加量等因素对产物长径比和晶体形貌的影响。采用XRD、SEM等分析手段对产物进行表征。结果表明,n(Al2O3)/n(SiO2)可以控制晶体尺寸的大小以及长径比,HF的存在影响晶体的成核及分散性。     

人参皂甙Rg3的分离提纯

研究了人参皂甙Rh2生产过程中所生成的副产品Rg3的分离提纯。用硅胶柱层析法从人参皂甙混合物中分离出单体Rg3的得率为样品的 16 %。再用化学法对Rg3进行拆分。 2 0 (S) 和2 0 (R) Rg3异构体 ,通过乙酰化反应生成极性相差较大的异构体 ,经硅胶柱层析得到两种产物 ,分别脱乙酰化后得到 2 0 (S) Rg3和 2 0 (R) Rg3。 2 0 (R) Rg3收率为 5 5 %。     

人参皂甙Rg3的分离提纯

研究了人参皂甙Rh2生产过程中所生成的副产品Rg3的分离提纯。用硅胶柱层析法从人参皂甙混合中分离出单体Rg3的得率为样品的16%。再用化学法对Rg3进行拆分。20（S）-和20（R）-Rg3异构体，通过乙酰化反应生成极性相差较大的异构体，经硅胶柱层析得到两种产物，分别脱乙酰化后得到20（S）-Rg3和20（R）-Rg3。20（R）-Rg3收率为55%。